WO2019175000A1 - Valve actuator, corresponding valve and corresponding machine - Google Patents

Abstract

The invention relates to a valve actuator comprising moving gear designed to cause a plug (7) of said gear to slide along a given axis between two extreme positions, the moving gear comprising a core (18) moving as one with the plug in terms of translational movement along the given axis, the actuator comprising a coil (28) surrounded by two rings (29, 30) made of ferromagnetic material, all three components being secured to a frame of the actuator in such a way as to surround the core which itself bears two magnets (23, 24) mounted in opposition on the core in the region of the coil, a ring (26) made of ferromagnetic materials separating the two magnets also flanked on the outside by two other rings (25, 27) made of ferromagnetic material. The invention also relates to a valve and to a machine each equipped with such an actuator.

Description

 Valve actuator, valve and corresponding machine

1 / invention relates to a valve actuator.

 The invention also relates to a valve equipped with such an actuator.

 The invention also relates to a machine comprising such a valve and such an actuator as for example, and without limitation, a machine for transporting containers.

 BACKGROUND OF THE INVENTION In order to allow the linking of an inlet with two different outlets, three-way valves are known today.

 These valves are generally associated with pneumatic valve actuators which is incompatible with aseptic media meeting very strict hygiene and safety standards. Therefore, to be able to use this type of valve in an aseptic environment, it would be advisable to arrange the actuator out of the aseptic medium targeted which is of course impractical.

 To overcome this drawback, it has been envisaged to use actuators of electric valves. However, the actuator then has a tendency to heat up rapidly during operation, which is all the more problematic since the actuator is sometimes subjected to already considerable temperature constraints.

 OBJECT OF THE INVENTION

 An object of the invention is to provide a valve actuator less subject to heating.

 An object of the invention is also to propose a valve equipped with such an actuator.

 An object of the invention is also to provide a machine comprising such an actuator and such a valve.

BRIEF DESCRIPTION OF THE INVENTION The invention thus relates to a valve actuator comprising a moving element arranged to slide a buffer of said crew along an axis gives between two end positions, allowing the buffer in use to connect an inlet channel of the valve with at least one outlet of said valve, the mobile assembly comprising a core integral with translation of the buffer along the given axis.

 According to the invention, the actuator comprises a coil surrounded by two rings of ferromagnetic material, all three integral with a frame of the actuator so as to surround the core which itself carries two magnets mounted in opposition to the core at level of the coil, a ring of ferromagnetic material separating the two magnets also externally framed by two other rings of ferromagnetic material,

 the supply of the coil causing the attraction of one of the magnets and the repulsion of the other of the magnets carried by the core in the direction of supply of the coil, the cooperation of the pair of rings of the frame with respectively one of the pairs of rings of the core ensuring the locking of the buffer in each of its end positions when the coil ceases to be energized, the movable element comprising moreover at least two elastically deformable elements connected to the core in such a way that that the pairs of rings of the core are offset from the pair of rings of the frame during the locking of the buffer in each of its end positions.

In this way, the invention limits a risk of overheating of the actuator, the coil being fed only the time to switch the core (and therefore the buffer) from one position to another. This period of time is advantageously short (of the order of a few tens of milliseconds) which considerably limits the heating of the coil and therefore of the actuator. Advantageously, a single electrical pulse is sufficient to cause the passage of the buffer from one position to another.

 Such a valve actuator is advantageously usable in aseptic media by the use of electrical energy.

 It should be noted that the elastically deformable elements are arranged in such a way that each pair of rings of the core is offset from the pair of rings of the chassis when the core is locked: in this way, when feeding the coil the elements elastically deformable facilitate the tilting of the core (and therefore the buffer) from one position to another.

 Optionally, the elastically deformable elements are springs.

 Optionally, a first spring of the moving element is arranged between the core and the chassis and a second spring of the moving element is arranged between the buffer and a body of the valve,

 Optionally, the moving element comprises a third spring arranged between the core and the buffer.

 Optionally, the movable element comprises a sealing element arranged between the buffer and the frame of one actuator.

 Optionally, the sealing element is a bellows.

 Optionally, the actuator includes a proximity sensor for detecting the position of the core.

 Optionally, the sensor is an inductive sensor. The invention also relates to a valve comprising such a valve actuator.

The invention also relates to a machine comprising such a valve actuator and such a valve. Optionally, the machine comprises a control unit connected to the actuator for managing the pulse supply of the actuator coil.

 Other characteristics and advantages of the invention will emerge on reading the following description of a particular non-limiting embodiment of the invention.

 BRIEF DESCRIPTION OF THE DRAWINGS

 The invention will be better understood in the light of the description which follows with reference to the accompanying figures, among which:

 - Figure 1 is a sectional view of a valve actuator according to a particular embodiment of the invention and the associated valve, the buffer being in a first of its two end positions,

 FIG. 2 is a sectional view of the actuator and the valve illustrated in FIG. 1 when the buffer is in the second of its two end positions,

 FIG. 3 is a three-dimensional view of a part of a machine comprising the actuator and the valve illustrated in FIG.

 DETAILED DESCRIPTION OF A PARTICULAR EMBODIMENT

 OF THE INVENTION

Referring to the various figures, the valve actuator, generally designated 1, according to a particular embodiment of the invention is associated with a valve, generally designated 2. The valve 2 here comprises a valve body 3a in which are provided two outputs 4, 5 and an inlet channel 6 connected to the two outputs 4, 5, said valve body 3a being closed at a second end thereof by a cover 3b of the valve 2, the actuator 1 being mounted on the valve 2 at the first end of the valve body 3a. The valve 2 is here a so-called three-way valve. Said valve 2 and said actuator 1 are mounted together on a carousel 101 of a machine, generally designated 100, such as a container transport machine R (such as a container decontamination machine, a container filling machine. ..). In this case, the carousel 101 is equipped with a plurality of valves and valve actuators identical and shaped according to the particular embodiment of the invention.

 The valve 1 comprises a buffer 7 extending in the valve 2 so that here it is possible to translate between two end positions along a given axis X at the connection between the intake channel 6 and the two outlets 4, 5.

 In a first end position, the buffer 7 makes it possible to connect the admission channel 6 with the first outlet 4 (as illustrated in FIG. 1) while blocking the passage of a fluid towards the second outlet 5. In the second end position, the buffer 7 makes it possible for the inlet channel 6 to be connected to the second outlet 5 (as illustrated in FIG. 2) while blocking the passage of the fluid towards the first outlet 4.

 The buffer 7 comprises for this purpose two valves 8, 9 each valve 8, 9 is here shaped so as to have a body 12, 13 and a head 10, 11 to temporarily block the passage of the fluid by cooperation with seats in the Valve body 3a, the valves 8, 9 are also secured to one another by a spacer 14 connected at its ends respectively to one of the valve heads 10, 11.

Furthermore, the body 13 of the second valve 9 is shaped in a rod slidably received along the axis X in the lid 3b, which facilitates the guiding of said valve 9, the rod extending through the head 11 of the second valve 9, The second valve 9 comprises a first spring 15 which connects the second valve 9 to the valve 2 and more precisely here to the lid 3b of said valve 2. The first spring 15 here surrounds the body 13 of the second valve 9 and is attached to a first end to the head 11 of the second valve 9 and at a second end to the lid 3b. The first spring 15 is a coil spring. The first spring 15 extends along the axis X.

 The body 12 of the first valve 8 is shaped as a piston formed of a fixing rod 12a to the head 10 of the first valve 8 and a piston head 12b.

 In order to improve the seal between the actuator 1 and the valve 2, the first valve 8 comprises a sealing element extending between the head 10 of the first valve 8 and a wall 33 of the actuator 1. In this way, the sealing element surrounds the part of the body 12 of the first valve 8 which extends in the valve 2. The sealing element is here a bellows 19. The bellows 19 is for example based on polytetrafluoroethylene { better known under the acronym PTFE) or else in another elastic material.

 The wall 33 is for example integral with the second end of the actuator 2 mounted on the valve 2. The wall 33 is typically attached to a frame 16 of the actuator 1 (extending along the X axis) and mounted sealingly on the valve 2 via an O-ring 34. Second O-ring 35 is arranged between the frame 16 and the valve 2 substantially at the outer circumference of said frame 16. Preferably, at least the portion of the chassis 16 in contact with the valve 2 is polyetheretherketone (better known by the acronym PEEK). The frame 16 and the frame 3 are thus secured to one another.

In a particular way the head 10 of the first valve 8 and the bellows 19 are of one piece improving further the seal between the actuator 1 and the valve 2. In particular, the bellows 19 and the wall 33 are in one piece, further improving the seal between the actuator 1 and the valve 2. In this case, the bellows 19, the wall 33 and the head 10 of the first valve are all three in one piece.

 The buffer 7 thus comprises here:

 the first valve 8,

 the second valve 9, and

 - the spacer 14.

 The first valve 8 furthermore comprises:

 - the head 10,

 the body 12 comprising the fixing rod 12a and the piston head 12b,

 - the bellows 19,

 - and here the wall 33.

 The second valve 9 furthermore comprises:

 - the head 11,

 the body 13, and

 - the first spring 15.

 The valve 1 also comprises a slider 17 which is arranged in the frame 16 to slide the buffer 7 along the X axis between its two end positions.

 The slider 17 comprises for this purpose a core 18 extending rectilinearly along the X axis in the frame 16 so as to be slidably mounted in the frame 16 along the X axis.

 The core 18 is connected at a first of its ends to the pad 7 so as to be integral in translation of the pad 7 along the axis X. The core 18 is here connected to the piston head 12b of the body 12 of the first valve 8 is at the part of the first valve 8 extending in the actuator 1 and out of the valve 2.

According to a preferred embodiment, the core 18 and the buffer 7 are not directly attached to each other but interconnected by means of a second spring 21 of the slider 17, second spring 21 which is therefore fixed at a first end to the core 18 and at a second end to the buffer 7 (here at the piston head 12b of the body 12 of the first valve 8), the second spring 21 is a coil spring. The second spring 21 thus extends along the axis X.

 Not only the second spring 21 makes it possible to transmit the forces between the core 18 and the buffer 7, but in addition the second spring 21 makes it possible to damp the movement of the buffer 7 when the buffer 7 moves between its two end positions. In addition the second spring 21 makes up the clearance between the race of the core 18 and the shorter one of the buffer 7.

 The slider 17 furthermore comprises a third spring 22 which connects the core 18 to the frame 16. Typically the third spring 22 is fixed at one of its ends to the frame 16 and to a second of its ends at the core 18, here at the level of the end of the core 18 opposite that to which is fixed the second spring 21. The third spring 22 is a helical spring. The third spring 22 thus extends along the axis X.

 In particular, the first spring 15 and the third spring 22 have a lower stiffness than the second spring 21. Typically, the second spring 21 has a stiffness of between 25 and 35 Newton per millimeter. The first spring 15 and the third spring 22 have stiffness of less than 1 Newton per millimeter. Preferably, the first spring 15 has a greater stiffness than that of the third spring 22,

 The slider 17 therefore comprises:

 - the nucleus 18,

the second spring 21, and the third spring 22,

 The core 18 is thus mounted in the frame 16 only via the second spring 21 and the third spring 22,

 The valve 1 thus makes it possible to create a mobile unit E composed of elements linked in translation along the axis X. The mobile unit E thus comprises here the buffer 7 and the slider 17 in succession:

 the first spring 15,

 the second valve 9,

 - the spacer 14,

 the first valve 8,

 the second spring 21,

 - the nucleus 18,

 the third spring 22.

 Therefore a displacement of the core 18 causes a displacement of the buffer 7 (through the second spring 21) along the axis X.

 The core 18 furthermore comprises two magnets 23, 24 mounted in opposition on the core 18 and separated from each other by a ring 26 of ferromagnetic material, the two magnets 23, 24 being also externally framed by two other rings 25, 27 made of ferromagnetic material. .

 Along the axis X, are thus successively mounted on the core 18:

 a first ring 25 made of ferromagnetic material,

a first magnet 23,

 a second ring 26 made of ferromagnetic material,

a second magnet 24,

 a third ring 27 made of ferromagnetic material.

 The magnets 23, 24 and the rings 25, 26, 27 are further shaped to be coaxial with the core 18 and the X axis and to externally surround the core 18.

The magnets 23, 24 and the rings 25, 26, 27 are attached to the core 18 so as to be in contact with each other. others. They thus define a first pair of rings formed of the first ring 25 and the second ring 26 and a second pair of rings formed of the second ring 26 and the third ring 27.

 Furthermore, the actuator 2 comprises a coil 28 fixed to the frame 16 so as to surround externally the core 18 and the magnets 23, 24 and rings 25, 26, 27 that the core 18 carries. The coil 28 is therefore coaxial with the core. 18.

 The actuator 2 further comprises a fourth ring 29 of ferromagnetic material and a fifth ring 30 of ferromagnetic material fixed to the frame 16 so as to surround externally the core 18 and the magnets 23, 24 and rings 25, 26, 27 that the core 18 door. The fourth ring 29 and the fifth ring 30 are thus coaxial with the core 18. The fourth ring 29 and the fifth ring 30 form a third pair of rings.

 The fourth ring 29 is juxtaposed with the first annular face of the coil 28 and the fifth ring 30 is juxtaposed with the second annular face of the coil 28, said fourth 29 and fifth 30 rings not however touching the coil 28.

 The rings 25, 26, 27, 29, 30 are for example stainless steel 630.

 The magnets 23, 24 are for example neodymium.

 The axis of the core 18 carrying the magnets 23, 24 and the rings 25, 26, 27 is for example made of metallic material

(like stainless steel such as 304 stainless steel). Preferably, the axis is extended at at least one of its two ends (and preferably at both ends) by buffers belonging to the core 18. The buffers are typically made of a plastic material (such as PEEK).

Preferably, the frame 16 comprises a carcass 20 of metal material surrounding circumferentially at least the third pair of rings and the coil 28, In particular, no layer of dedicated insulating material is arranged between the carcass 20 and the third pair of rings and the coil 28. The carcass 20 thus fills the same function as the washers 29, 30 and 25, 26, 27 closing lines of fields. Preferably, the carcass 20 is in a ferromagnetic material such as stainless steel 630.

 The actuator 1 further comprises a connector 31 for connecting the coil 28 to a power source.

 Preferably, the actuator 1 comprises at least one sensor 32 for determining the position of the buffer 7. For this purpose, the actuator 1 here comprises a sensor 32 for detecting the position of the core 18 (representative of that of the buffer 7) . For example, the sensor 32 is of the inductive type. The sensor 32 is typically fixed to the frame 16 so as to be arranged in the extension of the core 18 along the axis X. The sensor 32 is thus arranged in a glove finger 36 located at the first end of the actuator 1 The thermowell 36 is for example made of PEEK.

 The core 18 having a detection finger 37 made of a suitable material, finger 37 fixed to the free end of the core 18. In this way, according to the distance of the finger 37 from the sensor 32 along the X axis , the sensor 32 can estimate in which position is the core 18 and therefore in which position is the buffer 7.

 The frame 16 therefore allows the slider 17 and the sensor 32 to be received and to isolate them from the outside.

Thus, in use, the supply of the coil 28 causes the attraction of one of the magnets and the repulsion of the other magnets in the direction of supply of the coil 28, the cooperation of the pair of rings of the chassis 16 with respectively one of the pairs of rings of the core 18 ensuring the locking of the buffer 7 in each of its end positions when the coil 28 ceases to be powered.

 As illustrated in Figure 1, in a first position connecting the inlet channel 6 with the first output 4, the buffer 7 is in a first end position.

 To rock the buffer 7 in its second end position, it feeds the coil 28 in a first direction. This causes the attraction of the first magnet 23 and the repulsion of the second magnet 24 and therefore a translation of all the aforementioned mobile assembly E along the X axis.

 The displacement of the core 20 causes the solidarity

(by magnetic hooking) of the first pair of rings 25, 26 with the third pair of rings 29, 30; when the supply in the coil 28 is cut off, the core 18 thus remains in place thanks to this joining by the aforementioned pairs of rings.

 In this position, illustrated in FIG. 2, the buffer 7 is then in its second end position allowing the admission channel 6 to be connected to the second outlet 5.

 It is noted that the pairs of rings are however slightly offset from each other. This shift is desired and ensured by the action exerted by the springs on the core 18, in particular because the first spring 15 and the second spring 21 are constrained when the pad 7 is in its second end position.

With offset, it is indeed much easier to switch the core 18 back to its first position. For this purpose, to switch the buffer 7 back to its first end position, the coil 28 is fed in a second direction. This causes the attraction of the second magnet 24 and the repulsion of the first magnet 23 and thus a translation of all the aforementioned mobile assembly E along the axis X,

 The displacement of the core 20 causes the securing of the second pair of rings 26, 27 with the third pair of rings 29, 30; when the supply in the coil 28 is cut, the core 18 remains in place thanks to this connection by the aforementioned couples of rings.

 We find ourselves again locked in the first end position of the buffer 7 illustrated in Figure 1.

 It is noted that the pairs of rings are however slightly offset from each other. This offset is desired and ensured by the action exerted by the springs on the core 18, in particular because the third spring 22 is constrained and the second spring 21 is in the equilibrium state when the buffer 7 is in its first end position.

 Thanks to offset, it is indeed much easier to switch the core 18 back to its second position.

 The springs thus make it possible to keep the core 18 in a staggered position when the core is locked by magnetic hooking of the pairs of rings.

 Therefore, in case of breakage springs, the buffer 7 remains locked in one of its end positions which can detect a problem.

 The valve 2 thus described is a bistable valve 2 (the valve 2 having only two equilibrium positions).

The described associated actuator 1 is also simple in operation and low in energy, the coil 28 is not permanently powered. Indeed, a simple "positive" or "negative" current pulse is sufficient to switch the buffer 7 from one end position to another. By "pulse" is meant here a duration less than 50 milliseconds and preferably less than 35 milliseconds,

 1 / intensity of the current flowing through the coil 28 is also low, of the order (in absolute value) of a few amps, and preferably less than 3 amperes.

 The actuator 1 is connected to a control unit of the machine 100 (unit not shown here) which is configured to supply the coil 28 of the actuator 1 in pulses.

 Furthermore, the actuator 1 is electrically controlled which allows to arrange it even in aseptic media.

 In addition, the actuator 1 is sealingly mounted on the valve 2.

 Naturally, the invention is not limited to the embodiment described and variations can be made without departing from the scope of the invention as defined by the claims.

In particular, although here a three-way valve has been described, the actuator may be associated with other types of valves and for example a two-way valve. The actuator may thus have a shape other than that described and for example present a buffer with a single valve, the actuator then only needs two springs to keep the core rings offset from those of the chassis, a first spring being arranged between the pad and the core and a second spring being arranged between the core and the frame of the actuator. This will rebalance the forces exerted by the springs on the core vis-à-vis the embodiment that has been described here so that the ring couples remain offset when locking the core in position. Moreover, the core and the buffer can be directly attached to each other (possibly with a game of catch-up, the core and the buffer not necessarily having the same race). It will be possible to dispense with the spring connecting the core to the buffer. Alternatively, another connecting element that a spring can connect the core to the pad as a cushion elasto material or any other elastically deformable element.

 In the same way, it will be possible to use other elastically deformable elements to replace the first spring and / or the third spring such as a cushion of elastomeric material.

 The wall to which is attached the bellows of the valve may not be part of the bellows.

 The actuator could be free of a metal carcass, the rings alone enough to the looping of the field lines.

 The sensor described may be capacitive type, Hall effect ...

Claims

1. Valve actuator comprising a moving element arranged to slide a buffer (7) of said crew along a given axis (X) between two end positions, enabling the buffer in use to connect an inlet channel (6). ) of the valve with at least one outlet of said valve, the mobile assembly comprising a core (18) integral in translation of the buffer along the given axis (X), the actuator comprising a coil (28) surrounded by two rings (29, 30) of ferromagnetic material, all three integral with a frame of the actuator so as to surround the core which itself carries two magnets (23, 24) mounted in opposition on the core at the coil, a ring (26) of ferromagnetic material separating the two magnets also externally framed by two other rings (25, 27) of ferromagnetic material,  the supply of the coil causing the attraction of one of the magnets and the repulsion of the other of the magnets carried by the core in the direction of supply of the coil, the cooperation of the pair of rings of the frame with respectively one of the pairs of rings of the core ensuring the locking of the buffer in each of its end positions when the coil ceases to be energized, the mobile element comprising moreover at least two elastically deformable elements (15, 22) related to the core so that the core ring pairs are offset from the frame ring torque when locking the pad in each of its end positions.  2. An actuator according to claim 1, wherein the elastically deformable elements are springs. Actuator according to claim 2, in a first spring (22) of the moving element is arranged between the core and the chassis and a second spring (15) of The mobile equipment is arranged between the buffer and a body of the valve.  4. An actuator according to claim 3, wherein the movable element comprises a third spring (21) arranged between the core and the buffer.  5. An actuator according to one of the preceding claims, wherein the movable element comprises a sealing element arranged between the buffer (7) and the frame (16) of the actuator.  An actuator according to claim 5, wherein the sealing member is a bellows (19).  Actuator according to one of the preceding claims, wherein the actuator comprises a proximity sensor (32) for detecting the position of the core.  The actuator of claim 7, wherein the sensor (32) is an inductive sensor.  9. Valve comprising a valve actuator according to one of the preceding claims.  10. Machine comprising such a valve actuator according to one of claims 1 to 8 and a valve associated with said valve actuator.  11. Machine according to claim 10 comprising a control unit connected to the actuator for managing the pulse supply of the actuator coil.